| 1 | Laboratory Evaluation of the Molluscicidal Activity of Pulsatilla Chinensis(Bunge)Regel Saponins against the Snail Oncomelania Hupensis显示文摘Objective To observe the toxicity of Pulsatilla chinensis(Bunge) Regel saponins(PRS) against Oncomelania hupensis(O.hupensis).Methods O.hupensis snails were exposed to 40% and 80% of 24 h LC50 of PRS for 24 h,and then choline esterase(CHE),alanine aminotransferase(ALT),alkaline phosphatase(ALP),lactate dehydrogenase(LDH) activities in cephalopodium and liver of snails were determined.Niclosamide(NIC) was used as the reference molluscicide.Zebra fish lethality test was evaluated to non-target aquatic species of PRS.Results The molluscicidal activity of PRS(LC50 at 24 h:0.48 mg/L) was similar to that of NIC(LC50 at 24 h:0.16 mg/L).Significant alterations about CHE,ALP,and ALT activities both in the cephalopodium and the liver of snails were observed when O.hupensis was exposed to 40% and 80% LC50 of PRS or NIC for 24 h.PRS and NIC could not affect LDH activity in the cephalopodium and the liver.Lower toxicity to fish of PRS was observed up to the highest concentration tested than NIC.Conclusion PRS,as compared with the reference molluscicide NIC,is thought to be used for the control of harmful vector snails safely. | CHEN Yan Qin XU Qiong Ming LIU Yan Li LI Xiao Ran YANG Shi Lin ZHUGE Hong Xiang | 2012 | Biomedical and Environmental Sciences2012，25，2： | 8 |
| 2 | Sample preparation for isotopic determination of boron in clay sediments显示文摘The procedures of sample preparation for isotopic determination of boron in clay sediments is very cumbersome, by far, there haven't been relevant reports on that. In order to establish an effective method for sample preparation, a series of experiments were carried out. In this paper, boron in clay sediments was extracted with HCl solution and purified by two-step ion exchange method. Extracted HCl solution should be adjusted to alkalescency before passing through the Amberlite IRA 743 resin column due to the fact that Amberlite IRA 743 resin absorbs boron only from alkalescent solution. However, a mass of hydroxides of Al and Fe will be precipitated when the extracted HCl solution becomes alkalescent. Hydroxides of Al and Fe have a strong adsorption capacity for boron, which can cause boron isotope fractionation. To treat precipitated hydroxides of Al and Fe, four procedures, namely direct ion exchange (DRIE), decationizing ion exchange (DCIE), once sedimentation ion exchange (OSIE) and repeated sedimentation ion exchange (RSIE) were used and assessed. The influences of the four procedures on separation and extraction and isotopic composition of boron in experimental solutions and clay sediments were also discussed. According to the results, the DRIE, DCIE and OSIE are improper. The result of sample determination indicates that when extracting boron via RSIE, with the increase of precipitation times, there's an obvious decrease in boron content in the precipitated hydroxides while a sharp increase in recovery of boron and it is favorable for weakening the influence of boron isotope fractionation. But the process of RSIE is time consuming and it may introduce boron. It needs further research to establish a more effective sample preparation method for isotopic deter- mination of boron in clay sediments. | ZHANG Yanling XIAO Yingkai MA Yunqi ZHUGE Qin LIU Zhiqi HE Maoyong LUO Chongguang MA Haizhou | 2013 | Chinese Journal Of Geochemistry2013，32，2： | 2 |
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